What does the artificial womb mean for the future of fertility and neonatal care?

Brenda Lau, 28 Apr 2017

Only half of preemies born before 24 weeks survive, and those who survive face long-term medical challenges

When babies are born prematurely at 24 weeks' gestation, "it is very clear they are not ready to be here," says Emily Partridge, a research fellow at the Children's Hospital of Philadelphia.

Only wearing miniature diapers, preemies are hooked up to multiple tubes and cradled in plastic incubators. In most cases, the IV lines deliver sedatives to help them cope with the ventilators attached to their faces. Only half of those born before 24 weeks survive, and "among those that survive, the challenges are things we all take for granted, like walking, talking, seeing, hearing," says Kevin Dysart, a neonatologist at the Children's Hospital.

But within a decade or so, babies born between 23 and 25 weeks could be stored into a special bag filled with lab-made amniotic fluid to gestate for another month inside an artificial womb.

How Philadelphia's artificial womb works

The new technology has been successfully tested on lambs in a study by Partridge and other researchers from Philadelphia. Eight 105 to 115 days old premature lambs - a close animal model for human foetuses - were placed in liquid-filled, artificial wombs.

Hooked up to an oxygenator, the lambs "breathe" through the umbilical cords that transport blood the foetuses pump on their own through their tiny hearts. The amniotic fluid also boosts lung growth, and development of the intestines, as well as protects the foetuses from infections.

This allowed the lambs to further develop for four weeks - longer than previous similar attempts. The lambs' vital organs also developed normally and managed to open their eyes, grew in size and even had coats of white wool.

The researchers say that animal studies will be completed within two years, and if approved, the wombs can be tested on human preemies within three to five years. Their ultimate aim is to reduce the estimated USD43 billion that prematurity costs the US medical system each year.

The challenge to make it acceptable for society

A lamb is pictured after four (left) and 28 days (right) in the artificial womb. Photo credit: Nature Communications

Hypothetically, babies hooked up to this apparatus would need to be delivered by C-section and during the operation, the foetus will be administered a drug that would prevent it from breathing in air from the outside world. Within seconds, it would be submerged in the polyethylene bag, which mimics womb conditions. The entire process takes two minutes.

"I don't want this to be visualised as foetuses hanging on the wall in the bags," said Alan Flake, a foetal surgeon at Children's Hospital of Philadelphia and an author of the study.

He assures that it will look similar to a traditional neonatal incubator, potentially equipped with a camera to monitor the foetus and to assure anxious parents. The doctors could even mimic the mother's heartbeat to recreate the exact conditions of a womb.

The 2074 vision of ectogenesis

The study has readily sped up J.B.S. Haldane's - a hugely influential science populariser - prediction in 1924. He said that ectogenesis, a pregnancy that occurs in an artificial environment, would be the norm by 2074.

Previous studies in 1996 have already saw Japanese researchers succeeding in maintaining goat foetuses for as long as three weeks, but the team faced problems with circulatory failure and other technical difficulties.

Others such as Dr Helen Hung-Ching Liu's research in 2003 hope to help women who are unable to conceive and gestate babies. The Director of the Reproductive Endocrine Laboratory at the Centre for Reproductive Medicine and Infertility at Cornell University and her team succeeded in growing a mouse embryo, almost to full term.

More recently, she managed to grow a human embryo for ten days in an artificial womb, but was limited by the legislation that imposes a 14-day limit on such research projects.

The ongoing debate of ectogenesis

While pro-ectogenesis groups argue that artificial wombs would make preserve or boost the health of mothers and foetuses and also allow women who have damaged or medically dysfunctional uteruses to bear children, the question of whether people would be comfortable using it, remains.

Bioethicists also have suggested that ectogenesis could stop the surrogate trade, but on the other hand, monitoring the health of babies out of their natural environment also creates risks.

Biologically, ectogenesis seems like an epitome of futuristic propagation but the technology also raises philosophical and political concerns - states in the US might be encouraged to curtail abortions after, for instance, 20 weeks' gestation.

So whether this approach would work for human infants still remains an open question until science and technology has advanced enough to provide answers. MIMS